Causes

What is known, is that it’s most likely to occur in people aged between 60 and 80 and is usually rare in people below the age of 50. Nevertheless, it has been known to occur in people in their 20’s and 30’s but these cases are due to more unusual forms of pancreatic cancer, for example papillary or neuroendocrine tumours.

Pancreatic cancer is most likely to occur in people aged between 60 and 80.

Pancreatic cancer is fundamentally a genetic disease. It can be caused by mutations or changes in a person’s DNA. These mutations may be due to inheriting a faulty gene, meaning that we are born with them, or these changes may be acquired or develop after we are born. In most cases, cancer of the pancreas is not usually caused by the inheritance of faulty genes, however 5-10% of pancreatic cancers can be the result of these inherited changes, which indicates why cancer of the pancreas can run in some families.

5-10% of pancreatic cancers can be the result of inherited changes.

The acquired changes (changes that develop after we are born) can occur when mistakes are made when a cell replicates or divides. Cells in the body are continuously replicating in order to make new cells and replenish cells, which have died as part of the normal cell cycle. This process is regulated by DNA. When DNA is damaged, changes occur in these instructions and as a consequence may result in abnormal growth, such as a tumour.

Certain risk factors can also increase a person’s chance of acquiring these genetic changes, which can lead to the development of pancreatic cancer.

Risk Factors

Some of the known risk factors are:

Smoking
Exposure to cancer causing chemicals (carcinogens), such as those found in cigarette smoke, can significantly increase a person’s risk of pancreatic cancer. Tobacco smoking is a major risk factor, and those who smoke or have smoked are approximately two to three times more likely to develop cancer of the pancreas.

Age
The incidence of developing pancreatic cancer increases dramatically with age. About 80% of cases occur in people between the ages of 60 and 80.

Nutrition and Dietary factors
Diets with a high intake of meat and/or saturated fat, and a reduced intake of fruits and vegetables can increase the risk of pancreatic cancer.

Other dietary factors associated with a greater risk of cancer of the pancreas, include:

• Foods high in cholesterol
• Increased consumption of salt and smoked meats
• High intake of dehydrated and/or fried foods
• Over consumption of barbecued meat (exposure to the carcinogen heterocyclic aromatic amine [HCA])

Environmental

Those who are frequently exposed to certain pesticides and petroleum products may have an increased risk of pancreatic cancer. High rates of pancreatic cancer have been noted among industrial workers; for example the chemical manufacturing and metal industries.

Medical Conditions

Chronic pancreatitis
Patients who have chronic pancreatitis are 5 times more likely to develop pancreatic cancer. Chronic pancreatitis is characterised by recurrent inflammation of the pancreas. The most common cause of chronic pancreatitis is long-term alcohol abuse.

Diabetes Mellitus
There is a long-standing association with Diabetes Mellitus and an increased risk of developing pancreatic cancer. The explanation as to why this is the case is not well understood, thus further research is being conducted in order to understand the connection between cancer of the pancreas and Diabetes.

Previous surgery – Gastrectomy or Cholecystectomy
There appears to be an increased risk of developing pancreatic cancer in those who have had certain types of surgery, such as a gastrectomy (portion of stomach removed) to treat stomach ulcers for example, or those who have had a cholecystectomy (gallbladder removal). There are specific types of bacteria that can produce carcinogenic chemicals called nitrosamines as a result of these types of surgery, which may increase the risk of pancreatic cancer.

Hereditary Aspects of Pancreatic Cancer

It is important to remember that pancreatic cancer does not usually run in the family and often occurs by chance. However 5-10% of pancreatic cancers may be inherited (meaning that we are born with them) and there are a number of different gene mutations that can increase the risk of pancreatic cancer, such as:

Breast Cancer Gene 2 (BRCA2)
As many as 10-20% of pancreatic cancer cases are caused by inherited defects in the BRCA2 gene.

Peutz-Jeghers Syndrome
This has been linked to the growth of polyps (usually benign) in the stomach and intestines, as well as an increased risk of pancreatic cancer.

Familial Atypical Mole Melanoma (FAMMM)
Families with this mutation have a tendency to develop a large number of skin moles and melanomas, and may also be susceptible to cancer of the pancreas.

Hereditary Non-Polyposis Colorectal Cancer (HNPCC)
There is an inherited predisposition to develop colon cancer, stomach cancer, endometrial (uterine) and ovarian cancer as well as the risk of developing pancreatic cancer.

Familial Adenomatous Polyposis (FAP)
FAP is characterised by multiple colorectal adenomas and tumours of other organs and sites, and also connected to an increased risk of cancer of the pancreas.

Hereditary Pancreatitis
7-8% of patients with pancreatic cancer have a history of pancreatitis. This condition is characterised by frequent episodes of chronic pancreatitis (long-term inflammation of the pancreas) beginning from a relatively young age.

It should be noted that inherited or familial pancreatic cancer may also occur in the absence of any of these gene mutations. There are other rare gene mutations that can occur, and if relevant please consult your treating physician regarding these for further information.